This invention relates generally to improved apparatus for handling elongated paper roll tape of the type used with adding machines, calculators, and the like. More particularly, this invention relates to an improved paper tape roll control unit for supplying paper tape to and for simultaneously rewinding paper tape discharged from an adding machine or calculator or the like.
Adding machines, calculators and other types of business machines are well known of the type utilizing elongated strips of so-called paper tape. Typically, an elongated strip of paper tape is supplied in roll form and mounted on the adding machine or calculator, etc., by means of a rotatable spindle which permits the tape to be unrolled for supply to the business machine. The business machine commonly includes a roller platen or a similar mechanism for drawing the tape incrementally from the supply reel into association with a suitable printing head which applies numbers, letters, etc., onto the paper tape. In most cases, the paper tape is permitted to discharge from the machine freely in an unrestrained manner which commonly results in elongated, tangled strips of paper tape which fall onto the floor in an unsightly manner.
A wide variety of paper tape control devices have been proposed for use with adding machines and calculators and the like, particularly to include a take-up reel onto which used paper tape is rewound simultaneously with unwinding of the tape from the supply reel. Many such paper tape control devices are integrated directly into the associated business machine, thereby providing a relatively large and complicated business machine construction. Other paper tape control devices have been designed as add-on components for mounting onto a separate business machine. In the past, such add-on devices have commonly used friction or belt drive interconnections and the like between the paper tape and associated supply and take-up reels in attempts to rewind used tape onto the take-up reel as additional unused tape is fed to the machine from the supply reel. However, with the exception of the system described in applicant's U.S. Pat. 4,700,906, such mechanically linked supply/take-up reel arrangements for the most part have not adequately accounted for the inversely varying reel diameters as paper tape movement progresses. Other add-on systems have proposed the use of separate motors for driving the take-up reel independently of the supply reel or roller platen, as described, for example, in U.S. Pat. Nos. 3,338,531 and 3,447,657. However, such motor driven systems have relied upon substantially continuous motor operation in conjunction with an overrun clutch or the like to obtain intermittent rotation of the tape take-up reel. The prior art has not satisfactorily provided a simple and economical motor driven take-up reel adapted for intermittent motor energization.
The present invention relates to an improved paper tape control device of relatively simple, economical, and reliable construction, wherein a separate motor is provided for automatic intermittent advancement, of a take-up reel.